docs: def get_mesh_assets_by_site(self):
          """
          :returns: (Mesh instance, assets_by_site list)
          """
          assets_by_loc = general.groupby(self, key=lambda a: a.location)
          mesh = geo.Mesh.from_coords(list(assets_by_loc))
          assets_by_site = [
              assets_by_loc[lonlat] for lonlat in zip(mesh.lons, mesh.lats)]
          return mesh, assets_by_site